Stabilized chemical composition

ABSTRACT

Stabilized liquid agrochemical compositions are provided that comprise flowable, aqueous dispersion concentrates comprising a) a continuous aqueous liquid phase; b) at least one dispersed, solid phase comprising a dispersion of polymer particles having a mean particle size of at least one micron, wherein the outside surfaces of the particles comprise a colloidal solid material and wherein the particles have at least one agrochemically active ingredient distributed therein, optionally a non-porous particulate mineral that acts as a diffusion barrier to slow the release of the active ingredient, and optionally at least one non-cross-linkable mobile chemical such that the extraction of this chemical from the disperse phase renders it porous in a manner that allows the active ingredient to diffuse out. The colloidal solid is used to stabilize the polymenzable resin in an emulsion state during preparation.

The present invention relates to stabilized, liquid, chemicalcompositions, the preparation of such compositions and a method of usingsuch compositions, for example, to combat pests or as plant growthregulators.

BACKGROUND OF THE INVENTION

Agriculturally active ingredients (agrochemicals) are often provided inthe form of concentrates suitable for dilution with water. Many forms ofagricultural concentrates are known and these consist of the activeingredient and a carrier, which can include various components.Water-based concentrates are obtained by dissolving, emulsifying and/orsuspending agriculturally active materials in water. Due to therelatively complex supply chain for crop protection agents, suchconcentrate formulations can be stored for long periods and may besubjected during storage and shipping to extreme temperature variations,high-shear and repetitive vibration patterns. Such supply chainconditions can increase the likelihood of formulation failure such as,for example, flocculation, thickening and sedimentation.

In some cases it may be desirable to combine different agrochemicals ina single formulation taking advantage of the additive properties of eachseparate agrochemical and optionally an adjuvant or combination ofadjuvants that provide optimum biological performance. For example,transportation and storage costs can be minimized by using a formulationin which the concentration of the active agrochemical(s) is as high asis practicable and in which any desired adjuvants are “built-in” to theformulation as opposed to being separately tank-mixed. The higher theconcentration of the active agrochemical(s) however, the greater is theprobability that the stability of the formulation may be compromised, orthat one or more components may phase separate. In addition formulationfailure can be more challenging to avoid when multiple activeingredients are present because of physical or chemicalincompatibilities between these chemicals such as, for example, when oneactive ingredient is an acid, a base, an oily liquid, a hydrophobiccrystalline solid or a hydrophilic crystalline solid and the otheractive ingredient(s) has or have different properties.

It also may be desirable to improve the effectiveness of theagrochemicals by controlling the release rate of agrochemical into theapplication site from the formulation. In particular it may be desirableto combine agrochemicals in a single formulation and control theirrelease rates independently, for instance in cases where the modes ofaction of the agrochemicals renders them antagonistic if both aredelivered at the same rate.

In addition, spray tank mixes can contain a variety of chemicals andadjuvants that may interact and change the effectiveness of one or moreof the agrochemicals included therein. Incompatibility, poor waterquality and insufficient tank agitation can lead to reducedeffectiveness of sprays, phytotoxicity and can affect equipmentperformance.

Pesticide-comprising aqueous polymer dispersions with a mean particlesize of the dispersed particles of <1000 nm which are obtained fromminiemulsion polymerization of ethylenically unsaturated monomers areknown, for example, from US 2008/0171658. A limitation of polymerdispersions of this type is that the miniemulsions are stabilized byconventional surfactants and therefore have small particle size and highspecific surface area, which can result in a rapid release of theagrochemical(s) contained therein.

Considering the variety of conditions and special situations under whichagrochemical liquid concentrate formulation are stored, shipped and usedaround the world, there remains a need for aqueous polymer dispersionscomprising agrochemicals, including water-soluble, water-dispersible orwater-sensitive agrochemicals, having a mean particle size of thedispersed particles of >1000 nm and which provide additional stabilitybenefits under at least some of those conditions and situations. Thereis a further need for such formulations having high loading that arestable when diluted with water under a wide range of field conditions.There is yet a further need for such formulations that have controlledrelease rates of agrochemicals into the application site from theformulation and that work in complex aqueous systems and under a varietyof conditions.

Similar properties are required in formulations in non-agriculturalfields, for instance for controlled delivery of pharmaceutically activeingredients, for controlled delivery of flavors from foods, forcontrolled delivery of dyes or pigments, for controlled release offragrances from cosmetic or household products, or for controlleddelivery of enzymes and detergents in cleaning products. In theseindustries and others there is a need for the ability to prepare stableformulations of components that can be released to the target site uponapplication.

SUMMARY OF THE INVENTION

Stabilized liquid agrochemical compositions are provided which compriseflowable, aqueous dispersion concentrates comprising: a) a continuousaqueous liquid phase; b) at least one dispersed solid phase comprisingpolymer particles having a mean particle size of at least one (1)micron, wherein the outside surfaces of the particles comprise acolloidal solid material and wherein the particles have at least onechemical agent distributed therein. The polymer particles are preparedfrom either a curable or polymerizable resin or a solidifiablethermoplastic polymer. In one embodiment, the colloidal solid materialis present in the dispersed solid phase in an amount effective tostabilize the polymer resin in an emulsion state during the processwhich is used to prepare the dispersed phase. In another embodiment,surfactants are used in combination with the colloidal material in orderto more flexibly control the size of the polymer particles. In anotherembodiment, the chemical agent is a solid and is distributed within thedispersed solid phase, or is a liquid and is distributed within thedispersed solid phase. In a further embodiment the continuous liquidphase is water or is a mixture of water and either a water-miscibleliquid or a water-soluble solid. In another embodiment the polymerparticles also contain a non-cross-linkable mobile chemical such thatthe extraction of this chemical from the dispersed solid phase rendersit porous in a manner that allows the chemical agent to diffuse out fromthe dispersed phase. In another embodiment, the polymers forming thepolymer particles contain hydrophilic groups that hydrate on exposure towater, thereby increasing the permeability of the polymer matrix andallowing the chemical agent to diffuse out from the dispersed phase. Inanother embodiment, the dispersed solid phase comprises polymerparticles prepared by solidifying a thermoplastic polymeric resin,curing a thermoset resin or polymerizing a thermoplastic resin. When theat least one chemical agent is an agrochemically active ingredient, thecompositions of the invention can be used directly or with dilution tocombat pests or as plant growth regulators.

In accordance with one embodiment of the invention, it has been foundthat aqueous dispersion concentrates of agrochemically activeingredients in an aqueous liquid can be prepared by using polymerized,cured or solidified polymeric resin to entrap the agrochemically activeingredients in a polymer matrix when a colloidal solid is used tostabilize the polymer resin in an emulsion state during the curingreaction or solidification process. At least one agrochemically activeingredient can be distributed within the polymer matrix which isdispersed as particles within the continuous aqueous liquid phase. Otheractive ingredients may optionally be dispersed, dissolved, emulsified,microemulsified or suspended within the continuous phase.

The release rate of agrochemically active ingredients from the dispersedsolid phase can be controlled by the optional incorporation within thedispersed phase of mobile non-cross-linkable molecules, where thesemolecules are chosen to be insoluble or partially soluble in the aqueouscontinuous phase, miscible or immiscible with the polymer resin thatwill form the particulate polymer matrix, soluble in water or some othermedium to which the formulation will be exposed upon use, and ofmolecular dimensions such that the voids they create in the dispersephase upon extraction, allow the desired release of the agrochemicallyactive ingredients. The mobile non-cross-linkable molecules may bepresent in the dispersed solid phase either as a molecular dispersion(if miscible with the polymer resin), or as discrete inclusions (ifimmiscible with the polymer resin).

The release rate of agrochemically active ingredients from the dispersedsolid phase can be further controlled by the optional incorporationwithin the dispersed phase of non-porous particulate minerals as adiffusion barrier. For purposes of the present invention, non-porousmeans that the mineral lacks pores larger than individual molecules ofthe agrochemically active ingredients, such that the diffusioncoefficient of the agrochemical through particles of the mineral is lessthan 10⁻¹⁵ m²/s.

The aqueous dispersion concentrates of the invention have a usefullylong period of protection for water-soluble, water-dispersible,water-sensitive and other agrochemicals such that the chemical andphysical stability of the formulation is improved and which provides apractical utility in terms of storage, shipment and use. The dispersionconcentrates of the invention also conveniently allow the combination ofmultiple active ingredients in a single formulation, irrespective ofwhether they are liquids or solids, by incorporating them separately ortogether in polymer matrix particles that are mutually physicallycompatible. The dispersion concentrates of the invention also providethe ability to control the release rate of the agrochemical into thetarget site from the concentrate or an end-use dilute formulation and toenhance biological performance against target pests.

The aqueous dispersion concentrates of the invention have utility alsooutside the agricultural field where there is need to prepare stableformulations and deliver chemical agents to a target site. For thesepurposes the agrochemicals may be replaced with other chemical agents asrequired. In the context of the present invention, chemical agentstherefore include any catalyst, adjuvant, vaccine, genetic vector, drug,fragrance, flavor, enzyme, spore or other colony forming unit (CFU),detergent, dye, pigment, adhesive or other component where release ofthe chemical agent from the formulation is required. In addition theaqueous dispersion concentrates may be dried to prepare a powder orgranular product as desired.

The polymerizable resins suitable for use in preparing the dispersedphase cured polymer matrix can be selected from monomers, oligomers orprepolymers which are polymerizable to either thermoset or thermoplasticpolymer particles. In accordance with the invention, the disperse phasepolymer matrix also can be formed by dissolving polymers in a volatile,water-immiscible solvent that also contains at least one agrochemical,stabilizing this solution in water as a Pickering emulsion usingcolloidal stabilizers, and then heating this emulsion to evaporate thevolatile solvent and form a disperse solid phase of a thermoplasticpolymer matrix. In addition, the disperse phase polymer matrix can beformed by dissolving or suspending at least one agrochemically activeingredient in a non-aqueous liquid mixture comprising a melt of at leastone suitable thermoplastic polymer, emulsifying said dispersionconcentrate into a heated aqueous liquid to a mean droplet size of 1-200microns, which liquid also contains a colloidal solid as (Pickering)emulsion stabilizer; and cooling the emulsion to produce thermoplasticpolymeric particles.

The present invention further relates to polymer particles comprising anentrapped agrochemical that is either homogeneously or non-homogeneouslydistributed within such particles or present in the form of domainswithin such particles and wherein the outside surface regions of theparticles comprise a colloidal solid material.

The present invention also includes a method for combating orcontrolling pests or regulating the growth of plants at a locus such assoil or foliage which comprises treating said locus with a dispersionconcentrate according to the invention or dispersing a concentrateaccording to the present invention in water or liquid fertilizer andtreating said locus with the obtained diluted aqueous end-useformulation.

DETAILED DESCRIPTION OF THE INVENTION

Accordingly, in one embodiment, the aqueous liquid dispersionconcentrate compositions of the present invention comprise:

-   a) a continuous, aqueous liquid phase, optionally comprising at    least one chemical agent; and-   b) at least one dispersed, solid phase comprising polymer particles    having a mean particle size of at least one micron, wherein the    outside surfaces of the particles comprise a colloidal solid    material present in an amount effective to stabilize the polymer    particles in an emulsion state during the process which is used to    prepare the dispersed phase and wherein the polymer particles have    at least one chemical agent distributed therein.

In one embodiment, the chemical agents are agrochemically activeingredients.

In one embodiment, the colloidal solid material is a Pickering colloidemulsion stabilizer.

In one embodiment, the polymer particles comprise an entrappedagrochemical that is either homogeneously on non-homogeneouslydistributed within such particles or present in the form of domainswithin such particles.

In the context of the present invention, mean particle or droplet sizeindicates the volume-weighted mean, commonly designated D(v,0.5).

In one embodiment, the agrochemically active ingredient is a solid andis distributed within the dispersed solid phase or is a liquid and isdistributed within the dispersed solid phase.

In one embodiment, the agrochemically active ingredient (a.i.) in thedispersed phase is water-soluble, water-dispersible or water-sensitive.

In another embodiment, the dispersion concentrates for use in the liquidagrochemical compositions of the present invention are those that areformed using curing agents, monomers, oligomers, prepolymers or blendsthereof that exhibit a slow curing or polymerization reaction whencombined with the curing agents at ambient conditions. Particularlysuitable are those curing agents, monomers, oligomers, prepolymers orblends thereof that exhibit no significant increase in viscosity underambient conditions for a period of at least 15 minutes, moreparticularly 30 minutes, most particularly 1 hour, after mixing with thecuring agent.

In accordance with one embodiment of the invention, polymerizablethermoset resins are understood to include all molecules that may beirreversibly polymerized or cured to form a polymeric matrix that doesnot melt or deform at elevated temperatures below the point of thermaldecomposition. The polymerization reaction may be initiated thermally,by addition of chemical curing agents or by suitable irradiation tocreate radicals or ions such as by visible, UV, microwave or otherelectromagnetic irradiation, or electron beam irradiation. Examplesinclude the phenolics, ureas, melamines, epoxies, polyesters, silicones,rubbers, polyisocyanates, polyamines and polyurethanes. In addition,bioplastic or biodegradable thermoset resins may be used including epoxyor polyester resins derived from natural materials such as vegetableoil, soy or wood and the like.

In accordance with another embodiment of the invention, polymerizablethermoplastic resins are understood to include all molecules that may bepolymerized or cured to form a polymeric matrix that can melt or deformat elevated temperatures below the point of thermal decomposition. Thepolymerization reaction may be initiated thermally, by addition ofchemical curing agents or by suitable irradiation to create radicals orions such as by visible, UV or other electromagnetic irradiation, orelectron beam irradiation. Examples of suitable ethylenicallyunsaturated monomers include styrene, vinyl acetate, α-methylstyrene,methyl methacrylate, those described in US 2008/0171658 and the like.Examples of thermoplastic polymers for polymer particles that can beprepared from in-situ mini-emulsion polymerization includepolymethylmethacrylate, polystyrene, polystyrene-co-butadiene,polystyrene-co-acrylonitrile, polyacrylate, polyalkyl acrylate,polyalkyl acetate, polyacrylonitrile or their copolymers.

In accordance with yet another embodiment of the invention, solidifiablethermoplastic resins are understood to include all molecules that may bedissolved in a volatile solvent such that the solvent may be evaporatedby heating to create a polymeric matrix that can melt or deform atelevated temperatures below the point of thermal decomposition. Thevolatile solvent is chosen to be immiscible with the continuous aqueousphase and sufficiently volatile that it can be conveniently removed fromthe composition by heating to a temperature below that where anysignificant decomposition occurs. Examples include polymers of theethylenically unsaturated monomers described above, as well as polymerssuch as cellulose acetate, polyacrylates, polycaprolactone andpolylactic acid. There may also be mentioned polymethylmethacrylate,polystyrene, polyethylvinyl acetate, cellulose acetate, polyacrylate,polyacrylonitrile, polyamide, polyalkyleneterephthalate, polycarbonate,polyester, polyphenylene oxide, polysulfone, polyimide, polyetherimide,polyurethane, polyvinylidene chloride, polyvinyl chloride, polypropyleneand waxes, etc. In addition, bioplastic or biodegradable polymers suchas thermoplastic starch, polylactic acid, polyhydroxy alkanoate,polycaprolactone, polyesteramide are also suitable for use in preparingpolymer particles. Examples of volatile solvents include alkanes such ashexane and heptane, aromatic solvents such as benzene and toluene andhalogenated solvents such as dicholoromethane and trichloromethane.Other examples of suitable polymers and solvents are described inWO2011/040956A1.

In accordance with the invention, the polymer particles of the dispersedphase have a mean particle size of from 1 to 200 microns, moreparticularly from 1 to 100 microns and most particularly, from 2 to 80microns.

In one embodiment, suitable polymerizable resins and polymer solutionsare those which are substantially immiscible with the aqueous liquidused in the continuous phase.

In the context of the present invention, a colloidal solid material isone whose properties of interest are determined by its surfaceinteractions with other materials. Colloidal solids are thereforenecessarily those with high specific surface area, typically above 10m²/g. For example, colloidal solids are able to stabilize emulsions ofimmiscible liquids, as described for instance in WO 2008/030749. Whenserving for this purpose, such colloidal solids may be called Pickeringcolloids, colloidal emulsion stabilizers, or other equivalent terms.Functional tests are known for whether a colloidal solid can stabilizean emulsion as used herein. One such test is described infra inparagraph 110 below. Not all colloidal solids are able to stabilize anemulsion of any given pair of immiscible liquids, and such a functionaltest may used by those skilled in the art to identify a suitablecolloid.

As noted above, the release rate of agrochemically active ingredientsfrom the dispersed solid phase can be further controlled by the optionalincorporation within the dispersed phase of non-porous particulateminerals as a diffusion barrier. In some circumstances the samenon-porous particulate mineral used as a diffusion barrier within thedispersed phase may also serve as the colloidal emulsion stabilizer. Inthis situation the particulate mineral may be added in two separatepoints within the preparation process as described below—firstly to thedispersed phase concentrate in order to become incorporated within theparticles of the dispersed phase, and secondly to the aqueous continuousphase in order to stabilize the emulsion.

In another embodiment, the affinity of the aqueous liquids suitable foruse in the continuous phase a) for the agrochemically active ingredientdistributed in the dispersed solid phase b) is such that substantiallyall of the agrochemically active ingredient remains in the dispersedsolid phase and substantially none migrates to the continuous phase.Those skilled in the art will readily be able to determine whether aparticular aqueous liquid meets this criterion for a specificagrochemically active ingredient in question by following any standardtest procedure for determining the partition coefficient of a compound(in this case, the agrochemically active ingredient of the dispersedphase) between the continuous phase and the dispersed solid phase.Accordingly, the dispersed solid phase b) is immiscible with thecontinuous phase a).

In a further embodiment, the aqueous liquids suitable for use in thecontinuous phase a) are solutions of water-soluble solutes in water.

Water-soluble solutes suitable for use in the continuous phase includesalts such as halides, nitrates, sulfates, carbonates, phosphates,nitrites, sulfites, nitrides and sulfides of ammonium and of metals suchas those of groups 1 to 12 of the periodic table. Other suitable solutesinclude sugars and osmolytes such as polysaccharides, proteins, betainesand amino acids.

In one embodiment, the aqueous liquids suitable for use in thecontinuous phase a) are mixtures of water and a substantiallywater-miscible non-aqueous liquid. In the context of the invention, theterm “substantially water-miscible” means a non-aqueous liquid thatforms a single phase when present in water at a concentration up to atleast 50 wt %.

Substantially water-miscible non-aqueous liquids suitable for use in thecontinuous phase a) include, for example, propylene carbonate; awater-miscible glycol selected from ethylene glycol, diethylene glycol,triethylene glycol, propylene glycol, dipropylene glycol, tripropyleneglycol, butylene glycol, hexylene glycol and polyethylene glycols havinga molecular weight of up to about 800; an acetylated glycol such asdi(propylene glycol) methyl ether acetate or propylene glycol diacetate;triethyl phosphate; ethyl lactate; gamma-butyrolactone; a water-misciblealcohol such as propanol or tetrahydrofurfuryl alcohol; N-methylpyrrolidone; dimethyl lactamide; and mixtures thereof. In oneembodiment, the non-aqueous, substantially water-miscible liquid used inthe continuous phase a) is a solvent for at least one optionalagrochemically active ingredient.

In another embodiment, the aqueous, substantially water-miscible liquidused in the continuous phase a) is fully miscible with water in allproportions. Alternatively, the aqueous, substantially water-miscibleliquid used in the continuous phase a) is a waxy solid such aspolyethylene glycol having a molecular weight above about 1000 and themixture of this waxy solid with water is maintained in the liquid stateby forming the composition at an elevated temperature.

Those skilled in the art will appreciate that the quantities of waterand the nature and quantity of the non-aqueous, water-miscible liquid orwater-soluble solute can be varied to provide mixed aqueous liquidssuitable for use in the continuous phase a) and these quantities can bedetermined without undue experimentation. In one embodiment, the aqueouscontinuous phase comprises 5 to 95 wt %, more preferably 30 to 90 wt %,ethylene glycol with the balance being water. In another embodiment, theaqueous continuous phase comprises 5 to 95 wt %, more preferably 30 to90 wt %, glycerol with the balance being water.

In one embodiment, when the concentrate is diluted in water, some of theagrochemical slowly diffuses out of the polymer matrix particles. Theagrochemical release rate from the emulsified polymer particles in thespray tank can be adjusted, for example, by varying the size of thedispersed polymer particles in the concentrate, the concentration ofactive ingredient in the polymer, the pH of the spray tank dispersion,the optional inclusion of non-porous particulate minerals (as diffusionbarriers) in the polymer matrix, and the amount and nature of thethermoplastic polymers or polymerizable resin including monomers,oligomers, prepolymers and/or hardeners used to form the polymerparticles.

In this regard, the dispersed phase can also include one or morenon-cross-linkable mobile chemicals such that the extraction of thischemical from the dispersed phase renders it porous in a manner thatallows the chemical agent to diffuse out from the disperse phase. Themobile chemical may be chosen to diffuse out rapidly within theformulation concentrate, such that the polymer matrix is rendered soporous that the agrochemical is rapidly released upon dilution in water.Alternatively the mobile chemical may be chosen to be of limitedsolubility in the aqueous continuous phase, such that the mobilechemical diffuses out of the polymer matrix slowly after the formulationhas been diluted in water or applied to its target location, so that theagrochemical is only substantially released at the target location.Examples include surfactants, solvents, oligomers, polymers, copolymers,acids, bases, natural or synthetic oils, natural or synthetic alcohols,substantially water-soluble compounds or substantially water-insolublecompounds. In a specific embodiment, the mobile chemical is selectedsuch that it has limited solubility in a particular aqueous continuousphase, for instance an organic acid may be chosen that is substantiallyinsoluble in an acidic aqueous continuous phase, yet upon dilution inwater or application to the target site, the pH is higher than withinthe dispersion concentrate such that the organic acid (mobile chemical)is dissolved out of the polymer matrix rendering it porous and allowingthe active ingredient to be released. In another specific embodiment themobile chemical is selected such that it has limited solubility inaqueous environments but high solubility in waxy materials such as aplant cuticle, so that the mobile chemical is only substantiallyextracted from the matrix on contact with a plant leaf, and the activeingredient is then mainly released only on the leaf surface.

In another embodiment, a pH-sensitive release of the agrochemical activeis achieved by creating a polymer matrix with excess amine groups. Ondilution the amine groups hydrate, but the rate and extent of hydrationincreases at lower pH. The pH on dilution in the spray tank can becontrolled by including within the dispersed phase base components, butafter application the pH eventually becomes neutral and the release rateincreases. Alternatively, a polymer matrix is created with excess acidicgroups or other bases than amines. The nature of the pH sensitivity canbe further adjusted by choosing acid or base groups of varyingrespective pKa or pKb values.

In another embodiment, the active ingredient release profile from thedispersed phase may be modified by incorporating cross-linkable monomersthat contain hydrophilic groups such that on dilution into water thepolymer matrix particles hydrate and expand so that the matrix becomesmore permeable. In a particular embodiment, the cross-linkable monomersare glycerol diglycidyl ether epoxy resin. In another particularembodiment, the cross-linkable monomers are polypropyleneoxidediglycidyl ether epoxy resin.

The non-cross-linkable mobile chemical in the disperse phase mayoptionally be selected to also perform as a surfactant or dispersantwithin the liquid dispersion concentrate that is used to prepare theliquid agrochemical compositions of the present invention. If selectedin this manner, the mobile chemical will adsorb to the surfaces ofparticles present in the dispersion concentrate and thereby stabilizethe dispersion of those particles. This behaviour will be observable inat least one of the following ways: the particles will be distributedindividually rather than as agglomerates within the dispersionconcentrate when observed microscopically, the viscosity of thedispersion concentrate will be reduced when the mobile chemical isadded, or the particles will have a greater tendency to remain withinthe disperse phase instead of being lost to the continuous phase whenthe liquid agrochemical compositions are prepared. Examples of suitablemobile chemicals useful for this purpose include copolymers of anα-olefin and an N-vinylpyrrolidone such as, for example, alkylatedvinylpyrrolidone copolymers such as the Agrimers (e.g., Agrimer® AL-22,based on 1-ethenylhexadecyl-2-pyrrolidinone) (International SpecialtyProducts (ISP) Corporation), or copolymers of an α-olefin and ethyleneglycol such as, for example Atlox 4914 of Croda Corp, or organosiliconsurfactants such as Silwet L-77 (Momentive Performance Chemicals).

In one embodiment, the aqueous liquid dispersion concentratecompositions of the present invention comprise a mixture of polymerparticles each containing one or more than one chemical agents (such asan agrochemically active ingredient). Each one of the chemical agent(s)is contained within the same or different dispersed phase polymerparticles, and each respective dispersed phase particle optionallyincludes a different mobile chemical and/or polymer matrix as describedabove, such that each chemical agent or agent mixture has a differentrelease profile. Optionally each respective solid dispersed phase mayhave different particle sizes.

In one embodiment, the aqueous liquid dispersion concentratecompositions of the present invention comprise a solid phase in the formof finely divided, suspended polymer particles comprising a colloidalsolid material at their outside surface and containing at least oneagrochemically active ingredient, where the mean particle diameter ofsuch polymer particles is generally below 200 microns, frequently below100 microns, for example in the range from 1-200, particularly in therange from 1-100 and especially in the range from 2-80 microns.

The term “agrochemically active ingredient” refers to chemicals andbiological compositions, such as those described herein, which areeffective in killing, preventing, or controlling the growth ofundesirable pests, such as, plants, insects, mice, microorganism, algae,fungi, bacteria, and the like (such as pesticidally active ingredients).The term may also apply to compounds that act as adjuvants to promotethe uptake and delivery of other active compounds. The term may alsoapply to compounds that control the growth of plants in a desiredfashion (e.g., plant growth regulators), to a compound which mimics thenatural systemic activated resistance response found in plant species(e.g., plant activator) or to a compound that reduces the phytotoxicresponse to a herbicide (e.g., safener). If more than one is present,the agrochemically active ingredients are independently present in anamount that is biologically effective when the composition is diluted,if necessary, in a suitable volume of liquid carrier, e.g., water, andapplied to the intended target, e.g., the foliage of a plant or locusthereof.

Examples of agrochemical active ingredients suitable for use within thecontinuous phase a) or disperse phase b) in accordance with the presentinvention include, but are not limited to: fungicides such asazoxystrobin, chlorothalonil, cyprodinil, difenoconazole, fludioxonil,mandipropamid, picoxystrobin, propiconazole, pyraclostrobin,tebuconazole, thiabendazole and trifloxystrobin; herbicides such asacetochlor, alachlor, ametryn, anilofos, atrazine, azafenidin,benfluralin, benfuresate, bensulide, benzfendizone, benzofenap,bicyclopyrone, bromobutide, bromofenoxim, bromoxynil, butachlor,butafenacil, butamifos, butralin, butylate, cafenstrole, carbetamide,chloridazon, chlorpropham, chlorthal-dimethyl, chlorthiamid,cinidon-ethyl, cinmethylin, clomazone, clomeprop, cloransulam-methyl,cyanazine, cycloate, desmedipham, desmetryn, dichlobenil, diflufenican,dimepiperate, dimethachlor, dimethametryn, dimethenamid, dimethenamid-P,dinitramine, dinoterb, diphenamid, dithiopyr, EPTC, esprocarb,ethalfluralin, ethofumesate, etobenzanid, fenoxaprop-ethyl,fenoxaprop-P-ethyl, fentrazamide, flamprop-methyl, flamprop-M-isopropyl,fluazolate, fluchloralin, flufenacet, flumiclorac-pentyl, flumioxazin,fluorochloridone, flupoxam, flurenol, fluridone, flurtamone,fluthiacet-methyl, indanofan, isoxaben, isoxaflutole, lenacil, linuron,mefenacet, mesotrione, metamitron, metazachlor, methabenzthiazuron,methyldymron, metobenzuron, metolachlor, metosulam, metoxuron,metribuzin, molinate, naproanilide, napropamide, neburon, norflurazon,orbencarb, oryzalin, oxadiargyl, oxadiazon, oxyfluorfen, pebulate,pendimethalin, pentanochlor, pethoxamid, pentoxazone, phenmedipham,pinoxaden, piperophos, pretilachlor, prodiamine, profluazol, prometon,prometryn, propachlor, propanil, propazine, propham, propisochlor,propyzamide, prosulfocarb, pyraflufen-ethyl, pyrazogyl, pyrazolynate,pyrazoxyfen, pyributicarb, pyridate, pyriminobac-methyl, quinclorac,siduron, simazine, simetryn, S-metolachlor, sulcotrione, sulfentrazone,tebutam, tebuthiuron, terbacil, terbumeton, terbuthylazine, terbutryn,thenylchlor, thiazopyr, thidiazimin, thiobencarb, tiocarbazil,triallate, trietazine, trifluralin, and vernolate; herbicide safenerssuch as benoxacor, dichlormid, fenchlorazole-ethyl, fenclorim,flurazole, fluxofenim, furilazole, isoxadifen-ethyl, mefenpyr; alkalimetal, alkaline earth metal, sulfonium or ammonium cation of mefenpyr;mefenpyr-diethyl and oxabetrinil; insecticides such as abamectin,clothianidin, emamectin benzoate, gamma cyhalothrin, imidacloprid,cyhalothrin and its enantiomers such as lambda cyhalothrin, tefluthrin,permethrin, resmethrin and thiamethoxam; nematicides such asfosthiazate, fenamiphos and aldicarb.

Additionally, volatile agrochemically active ingredients such as thosewith a vapour pressure of at least 1 Pa at ambient temperature are alsosuitably entrapped in the dispersed phase b). Examples of such activeingredients include volatile nematicides such as methyl bromide, methyliodide, chloropicrin and 1,3-dichloropropene.

In one embodiment, the active ingredients in the continuous phase may bein the state of a solution, an emulsion, a microemulsion, a microcapsuleor a particle or fine particle. In the context of the present invention,a fine particle is one substantially smaller than the dimensions of thesolid polymeric particles of the dispersed phase, such that a plurality(at least 10) of active ingredient particles are within each particle ofthe dispersed phase, whereas a non-fine particle is one only slightlysmaller than the dimensions of the solid polymeric particles of thedispersed phase, such that each polymeric particle contains only a fewactive ingredient particles.

Further aspects of the invention include a method of preventing orcombating infestation of plant species by pests, and regulating plantgrowth by diluting an amount of concentrate composition with a suitableliquid carrier, such as water or liquid fertilizer, and applying to theplant, tree, animal or locus as desired. The formulations of the presentinvention may also be combined in a continuous flow apparatus with waterin spray application equipment, such that no holding tank is requiredfor the diluted product.

The aqueous liquid dispersion concentrate compositions can be storedconveniently in a container from which they are poured, or pumped, orinto which a liquid carrier is added prior to application.

The advantages of the aqueous liquid dispersion concentrate compositionsof the present invention include: storage-stability for extendedperiods, for example 6 months or longer at room temperature; multipleagrochemicals of different physical states may be conveniently combinedin dispersions of mutually compatible solid particles; the releaseprofiles of agrochemicals may be flexibly and independently controlled;simple handling is made possible for users because dilution is made withwater, or other liquid carrier, for preparation of application mixtures;reduced settling of the suspension during storage or on dilution; thecompositions can easily be resuspended or redispersed with only a minoramount of agitation and are not susceptible to coalescence when dilutionis made with fertilizer solutions for preparation of applicationmixtures.

The rate of application of the composition of the invention will dependon a number of factors including, for example, the active ingredientschosen for use, the identity of the pest to be controlled or the plantswhose growth is to be inhibited and the formulations selected for useand whether the compound is to be applied to foliage, soil, for or rootuptake or by chemigation. As a general guide, however, an applicationrate of from 1 to 2000 g active ingredient per hectare is suitable, inparticular from 2 to 500 g active ingredient per hectare.

In one embodiment, suitable rates for the agrochemically activeingredients used in the inventive compositions are comparable to theexisting rates given on the current product labels for productscontaining such actives. For example, Quadris® brand azoxystrobin can beapplied at a rate of from 112 g to 224 g a.i./hectare and Quilt™ brandpremix of azoxystrobin (75 g/L)/propiconazole (125 g/L) can be appliedat a rate of from 0.75-1.5 L/ha.

In one embodiment of the present invention, a further component may bepresent to control the pH of the water used to dilute the compositionprior to use.

If a solid agrochemically active material is present, the solid activeingredient may be milled to the desired particle size prior todispersion within the polymerizable resin (monomers, oligomers, and/orprepolymers, etc.) that will form the polymer matrix particles. Thesolid may be milled in a dry state using an air-mill or other suitableequipment as necessary, to achieve the desired particle size. Theparticle size may be a mean particle size of about 0.2 to about 20microns, suitably about 0.2 to about 15 microns, more suitably about 0.2to about 10 microns.

As used herein, the term “agrochemically effective amount” means theamount of an agrochemical active compound which adversely controls ormodifies target pests or regulates the growth of plants (PGR). Forexample, in the case of herbicides, a “herbicidally effective amount” isthat amount of herbicide sufficient for controlling or modifying plantgrowth. Controlling or modifying effects include all deviation fromnatural development, for example, killing, retardation, leaf burn,albinism, dwarfing and the like. The term plants refers to all physicalparts of a plant, including seeds, seedlings, saplings, roots, tubers,stems, stalks, foliage and fruits. In the case of fungicides, the term“fungicide” shall mean a material that kills or materially inhibits thegrowth, proliferation, division, reproduction, or spread of fungi. Asused herein, the term “fungicidally effective amount” or “amounteffective to control or reduce fungi” in relation to the fungicidalcompound is that amount that will kill or materially inhibit the growth,proliferation, division, reproduction, or spread of a significant numberof fungi. As used herein, the terms “insecticide”, “nematicide” or“acaricide” shall mean a material that kills or materially inhibits thegrowth, proliferation, reproduction, or spread of insects, nematodes oracarids, respectively. An “effective amount” of the insecticide,nematicide or acaricide is that amount that will kill or materiallyinhibit the growth, proliferation, reproduction or spread of asignificant number of insects, nematodes or acarids.

In one aspect, as used herein, “regulating (plant) growth”, “plantgrowth regulator”, PGR, “regulating” or “regulation” includes thefollowing plant responses; inhibition of cell elongation, for examplereduction in stem height and internodal distance, strengthening of thestem wall, thus increasing the resistance to lodging; compact growth inornamentals for the economic production of improved quality plants;promotion of better fruiting; increasing the number of ovaries with aview to stepping up yield; promotion of senescence of the formation oftissue enabling fruit to absciss;

defoliation of nursery and ornamental bushes and trees for mail-orderbusiness in the fall; defoliation of trees to interrupt parasitic chainsof infection; hastening of ripening, with a view to programming theharvest by reducing the harvest to one to two pickings and interruptingthe food-chain for injurious insects.

In another aspect, “regulating (plant) growth”, “plant growthregulator”, “PGR”, “regulating” or “regulation” also includes the use ofa composition as defined according to the present invention forincreasing the yield and/or improving the vigor of an agriculturalplant. According to one embodiment of the present invention, theinventive compositions are used for improved tolerance against stressfactors such as fungi, bacteria, viruses and/or insects and stressfactors such as heat stress, nutrient stress, cold stress, droughtstress, UV stress and/or salt stress of an agricultural plant.

The selection of application rates relative to providing a desired levelof pesticidal activity for a composition of the invention is routine forone of ordinary skill in the art. Application rates will depend onfactors such as level of pest pressure, plant conditions, weather andgrowing conditions as well as the activity of the agrochemically activeingredients and any applicable label rate restrictions.

The invention relates also to liquid agrochemical compositionscomprising

-   -   a) a continuous, aqueous liquid phase, optionally comprising at        least one agrochemically active ingredient (for example, in the        state selected from a solution or a dispersion such as emulsion,        a microemulsion, and/or a suspension of microcapsules or fine        particles); and    -   b) at least one dispersed, solid phase comprising polymer        particles prepared from either a curable or polymerizable resin        or a solidafiable thermoplastic polymer, wherein the outside        surfaces of the particles comprise a colloidal solid material        and wherein the particles have at least one agrochemically        active ingredient distributed therein.

A further aspect of the invention relates to a dilute aqueous spraycomposition for combating pests or regulating the growth of plants at alocus comprising

-   -   a) a continuous aqueous phase comprising a suitable liquid        carrier, such as water or a liquid fertilizer, in an amount        sufficient to obtain the desired final concentration of each of        the active ingredients in the spray composition;    -   b) at least one dispersed, solid phase comprising polymer        particles prepared from either a cureable or a polymerizable        resin or a solidifiable thermoplastic polymer, wherein the        outside surfaces of the particles comprise a colloidal solid        material and wherein the particles have at least one        agrochemically active ingredient distributed therein; and    -   c) optionally, at least one agrochemically active ingredient        dispersed, dissolved, suspended, microemulsified and/or        emulsified in the liquid carrier.

In another embodiment, the invention relates to a dilute pesticidaland/or PGR composition for ultra low volume (ULV) applicationcomprising:

-   -   a) a continuous phase comprising a carrier solvent having a        flash point above 55° C. in an amount sufficient to obtain the        desired final concentration of each of the active ingredients in        the ULV composition;    -   b) at least one dispersed, solid phase comprising polymer        particles prepared from either a cureable or a polymerizable        resin or a solidifiable thermoplastic, wherein the outside        surfaces of the particles comprise a colloidal solid material        and wherein the particles have at least one agrochemically        active ingredient distributed therein.

The invention relates also to a method for combating or preventing pestsin crops of useful plants or regulating the growth of such crops, saidmethod comprising:

-   -   1) treating the desired area, such as plants, the plant parts or        the locus thereof with a concentrate composition comprising:    -   a) a continuous aqueous liquid phase, optionally comprising at        least one agrochemically active ingredient, and also optionally        comprising at least one acidic or basic component;    -   b) at least one dispersed, solid phase comprising polymer        particles prepared from either a cureable or a polymerizable        resin or a solidifiable thermoplastic, wherein the outside        surfaces of the particles comprise a colloidal solid material        and wherein the particles have at least one agrochemically        active ingredient distributed therein; or    -   2) diluting the concentrate composition, if necessary, in a        suitable carrier, such as water, liquid fertilizer or a carrier        solvent having a flash point above 55° C., in an amount        sufficient to obtain the desired final concentration of each of        the agrochemically active ingredients; and then treating the        desired area, such as plants, the plant parts or the locus        thereof with the dilute spray or ULV composition.

The term plants refers to all physical parts of a plant, includingseeds, seedlings, saplings, roots, tubers, stems, flowers, stalks,foliage and fruits. The term locus refers to where the plant is growingor is expected to grow.

The composition according to the invention is suitable for all methodsof application conventionally used in agriculture, e.g. pre-emergenceapplication, post-emergence application, post-harvest and seed dressing.The compositions according to the invention are suitable for pre- orpost-emergence applications to crop areas.

The compositions according to the invention are suitable especially forcombating and/or preventing pests in crops of useful plants or forregulating the growth of such plants. Preferred crops of useful plantsinclude canola, cereals such as barley, oats, rye and wheat, cotton,maize, soya, sugar beets, fruits, berries, nuts, vegetables, flowers,trees, shrubs and turf. The components used in the composition of theinvention can be applied in a variety of ways known to those skilled inthe art, at various concentrations. The rate at which the compositionsare applied will depend upon the particular type of pests to becontrolled, the degree of control required, and the timing and method ofapplication.

Crops are to be understood as also including those crops which have beenrendered tolerant to herbicides or classes of herbicides (e.g. ALS-,GS-, EPSPS-, PPO-, ACCase and HPPD-inhibitors) by conventional methodsof breeding or by genetic engineering. An example of a crop that hasbeen rendered tolerant to imidazolinones, e.g. imazamox, by conventionalmethods of breeding is Clearfield® summer rape (canola). Examples ofcrops that have been rendered tolerant to herbicides by geneticengineering methods include e.g. glyphosate- and glufosinate-resistantmaize varieties commercially available under the trade namesRoundupReady® and LibertyLink®.

Crops are also to be understood as being those which have been renderedresistant to harmful insects by genetic engineering methods, for exampleBt maize (resistant to European corn borer), Bt cotton (resistant tocotton boll weevil) and also Bt potatoes (resistant to Colorado beetle).Examples of Bt maize are the Bt 176 maize hybrids of NK® (SyngentaSeeds). The Bt toxin is a protein that is formed naturally by Bacillusthuringiensis soil bacteria. Examples of toxins, or transgenic plantsable to synthesise such toxins, are described in EP-A-451 878, EP-A-374753, WO 93/07278, WO 95/34656, WO 03/052073 and EP-A-427 529. Examplesof transgenic plants comprising one or more genes that code for aninsecticidal resistance and express one or more toxins are KnockOut®(maize), Yield Gard® (maize), NuCOTIN33B® (cotton), Bollgard® (cotton),NewLeaf® (potatoes), NatureGard® and Protexcta®. Plant crops or seedmaterial thereof can be both resistant to herbicides and, at the sametime, resistant to insect feeding (“stacked” transgenic events). Forexample, seed can have the ability to express an insecticidal Cry3protein while at the same time being tolerant to glyphosate.

Crops are also to be understood to include those which are obtained byconventional methods of breeding or genetic engineering and containso-called output traits (e.g. improved storage stability, highernutritional value and improved flavour).

Other useful plants include turf grass for example in golf-courses,lawns, parks and roadsides, or grown commercially for sod, andornamental plants such as flowers or bushes.

Crop areas are areas of land on which the cultivated plants are alreadygrowing or in which the seeds of those cultivated plants have been sown,and also areas of land on which it is intended to grow those cultivatedplants.

Other active ingredients such as herbicide, plant growth regulator,algaecide, fungicide, bactericide, viricide, insecticide, acaricide,nematicide or molluscicide may be present in the formulations of thepresent invention or may be added as a tank-mix partner with theformulations.

The compositions of the invention may further comprise other inertadditives. Such additives include thickeners, flow enhancers,dispersants, emulsifiers, wetting agents, antifoaming agents, biocides,lubricants, fillers, drift control agents, deposition enhancers,adjuvants, evaporation retardants, freeze protecting agents, insectattracting odor agents, UV protecting agents, fragrances, and the like.The thickener may be a compound that is soluble or able to swell inwater, such as, for example, polysaccharides of xanthans (e.g., anionicheteropolysaccharides such as RHODOPOL® 23 (Xanthan Gum)(Rhodia,Cranbury, N.J.)), alginates, guars or celluloses; syntheticmacromolecules, such as modified cellulose-based polymers,polycarboxylates, bentonites, montmorillonites, hectonites, orattapulgites. The freeze protecting agent may be, for example, ethyleneglycol, propylene glycol, glycerol, diethylene glycol, saccharose,water-soluble salts such as sodium chloride, sorbitol, triethyleneglycol, tetraethylene glycol, urea, or mixtures thereof. Representativeanti-foam agents are silicone oils, polydialkylsiloxanes, in particularpolydimethylsiloxanes, fluoroaliphatic esters orperfluoroalkylphosphonic/perfluoroalkylphosphonic acids or the saltsthereof and mixtures thereof. Suitable antifoams arepolydimethylsiloxanes, such as Dow Corning® Antifoam A, Antifoam B orAntifoam MSA. Representative biocides include1,2-benzisothiazolin-3-one, available as PROXEL® GXL (Arch Chemicals).

The compositions of the invention may be mixed with fertilizers andstill maintain their stability.

The compositions of the invention may be used in conventionalagricultural methods. For example, the compositions of the invention maybe mixed with water and/or fertilizers and may be applied preemergenceand/or postemergence to a desired locus by any means, such as airplanespray tanks, irrigation equipment, direct injection spray equipment,knapsack spray tanks, cattle dipping vats, farm equipment used in groundspraying (e.g., boom sprayers, hand sprayers), and the like. The desiredlocus may be soil, plants, and the like.

Within the scope of the present invention are four different methods ofproducing dispersed phase polymeric particles containing chemicalagents, which are described in a manner wherein the chemical agents areagriculturally active ingredients. Each method results in a dispersedphase that comprises a solid polymer matrix with at least oneagriculturally active ingredient distributed therein, a colloidal solidmaterial at the surface, optionally a non-cross-linkable mobile chemicalsuch that the extraction of this chemical from the dispersed phaserenders it porous in a manner that allows the agrochemically activeingredient(s) to diffuse out from the dispersed phase, optionally apolymer matrix with hydrophilic groups that hydrate on exposure to waterand render the matrix permeable in a manner that allows theagrochemically active ingredient(s) to diffuse out from the dispersedphase, and optionally a non-porous mineral that renders the dispersedphase more impermeable to the agrochemically active ingredient(s).

The first method comprises the following steps:

-   -   1. preparing a dispersion concentrate by dissolving or        suspending at least one agrochemically active ingredient in a        non-aqueous curable liquid mixture comprising at least one        suitable cross-linkable resin (comprising monomers, oligomers,        prepolymers or blends thereof), optionally where the resin        contains hydrophilic groups, optionally a suitable hardener,        catalyst or initiator, and one or more optional components        selected from non-porous particulate minerals as diffusion        barrier and/or non-crosslinkable mobile chemicals,    -   2. emulsifying said dispersion concentrate in to an aqueous        liquid to a mean droplet size of 1-200 microns, which liquid        also contains a colloidal solid as (Pickering) emulsion        stabilizer, and, optionally, certain suitable hardener, catalyst        or initiator capable of diffusing into the dispersed uncured        resin droplets; and    -   3. effecting crosslinking or cure of the cross-linkable resin        mixture to produce cured thermoset polymeric particles.

The second method is substantially identical to the first, except thatthe dispersion concentrate comprises as non-aqueous liquid apolymerizable resin instead of a cross-linkable resin. Instead of acuring reaction in step 3, the dispersed phase particles are formed by apolymerization reaction, so that the resulting dispersed phase comprisesthermoplastic polymeric particles rather than thermoset polymericparticles.

The third method comprises the following steps:

-   -   1. dissolving or suspending at least one agrochemically active        ingredient in a non-aqueous liquid mixture comprising at least        one suitable solidifiable polymer dissolved in a volatile        solvent, and one or more optional components selected from        non-porous particulate minerals as diffusion barrier and/or        non-crosslinkable mobile chemicals;    -   2. emulsifying said solution in to an aqueous liquid to a mean        droplet size of 1-200 microns, which liquid also contains a        colloidal solid as (Pickering) emulsion stabilizer; and    -   3. effecting evaporation of the volatile solvent by heating the        emulsion to a temperature of about 30-120° C. for about 0.1-10        hr to produce solid thermoplastic polymer particles.

The fourth method of preparation comprises the following steps:

-   -   1. preparing a dispersion concentrate by dissolving or        suspending at least one agrochemically active ingredient in a        non-aqueous curable liquid mixture comprising a melt of at least        one suitable solidifiable thermoplastic polymer, and one or more        optional components selected from non-porous particulate        minerals as diffusion barrier and/or non-crosslinkable mobile        chemicals,    -   2. emulsifying said dispersion concentrate in to a heated        aqueous liquid to a mean droplet size of 1-200 microns, which        liquid also contains a colloidal solid as (Pickering) emulsion        stabilizer; and    -   3. cooling the emulsion to produce thermoplastic polymeric        particles.

In one embodiment, the dispersion concentrate is prepared by:

-   -   a. dissolving or suspending at least one agrochemically active        ingredient in a non-aqueous liquid mixture (premix) comprising        at least one suitable curable or polymerizable resin (comprising        monomers, oligomers, prepolymers or blends thereof), optionally        a suitable hardener, catalyst or initiator, and one or more        optional components selected from non-porous particulate        minerals (as diffusion barrier) and/or non-crosslinkable mobile        chemicals;    -   b. emulsifying said solution or suspension in to an aqueous        liquid to a mean droplet size of 1-200 microns, which liquid        also contains a colloidal solid as (Pickering) emulsion        stabilizer, and, optionally, certain suitable hardener, catalyst        or initiators capable of diffusing into the dispersed uncured or        unpolymerized resin droplets; and    -   c. effecting crosslinking, cure or polymerization of the resin        mixture to produce cured thermoset or polymerized thermoplastic        resin polymer particles having at least one agriculturally        active ingredient distributed therein and at least one colloidal        solid material at their surfaces and that after curing are        dispersed in the aqueous liquid.

In one embodiment, the dispersion concentrate is prepared by adding thehardener through the continuous phase, after the Pickering emulsion isformed, so that the dispersed phase premix is incapable of curing.Alternatively a first very slow-reacting hardener can be used in thedispersion concentrate, and then a second fast-curing hardener, anaccelerator or catalyst can be added through the continuous phase. Thesesecond agents are added to the continuous phase after the dispersedphase is emulsified, so they must be chosen to be miscible in thecontinuous phase. Suitable fast cure water-miscible hardeners includediethylene triamine, triethylene tetramine, xylene diamine, polyethyleneglycol diamine, and polyoxypropylene diamine. Mixtures of hardeners mayalso be employed for extra flexibility.

In one embodiment, the dispersion concentrate is prepared by adding apremix of the dispersed phase to a premix of the continuous phase,wherein:

-   -   1) the premix of the dispersed phase is prepared by blending        with a high shear mixer: at least one agriculturally active        ingredient, at least one suitable curable or polymerizable resin        monomer, oligomer, prepolymer or blend thereof, a suitable        hardener, catalyst or initiator, an optional non-crosslinkable        mobile chemical, and an optional particulate non-porous mineral        as diffusion barrier;    -   2) the premix of the continuous phase is prepared by blending        with low shear mixer: an aqueous liquid with a colloidal solid        as an emulsion stabilizer.

The resulting mixtures of the dispersed phase premix and the continuousphase premix are stirred under high shear conditions for a suitable timeto form a Pickering emulsion and then heated or exposed to light orother electromagnetic radiation conditions (UV, microwave), as needed,in order to polymerize the dispersed phase. The shear rate and durationof the emulsification may be readily determined by one skilled in theart, guided by the following observations: if the shear rate is too low,the emulsion and resulting polymer matrix particles are relativelycoarse and may be larger than desired; if the shear rate is instead toohigh or of too long a duration, the emulsion stabilizing colloideventually becomes so depleted from the continuous phase that any newinterfacial surface between the dispersed and continuous phases iseffectively unprotected, at which point rapid coalescence orheteroflocculation of the dispersed phase occurs and the Pickeringemulsion is effectively lost.

In one embodiment, the mixture of the dispersed phase premix and thecontinuous phase premix is stirred under high shear conditions for 5-10min and heated to a temperature of about 30-120° C. for about 0.1-10 hrin order to effect the curing reaction.

In one embodiment, the dispersion concentrate is prepared by:

-   -   a. dissolving or suspending at least one agrochemically active        ingredient in a non-aqueous liquid mixture comprising at least        one suitable polymer dissolved in a volatile solvent, and one or        more optional components selected from non-porous particulate        minerals (as diffusion barrier) and/or non-crosslinkable mobile        chemicals;    -   b. emulsifying said solution in to an aqueous liquid to a mean        droplet size of 1-200 microns, which liquid also contains a        colloidal solid as (Pickering) emulsion stabilizer; and    -   c. effecting evaporation of the volatile solvent by heating the        emulsion to a temperature of about 30-120° C. for about 0.1-10        hr to produce solid thermoplastic polymer particles having at        least one agriculturally active ingredient distributed therein        and colloidal solids at their surfaces and that are dispersed in        the aqueous liquid. If necessary more liquid may be added to the        continuous phase to replace any liquid lost during the        evaporation process.

Suitable polymerizable resins for use in preparing the solid polymerparticles of the dispersed solid phase include thermosets such as epoxyresins, phenolic resins, aminoplast resins and polyester resins.

Other suitable polymerizable resins for use in preparing the solidpolymer particles of the dispersed solid phase include thermoplasticsresins such as styrenes, methyl methacrylates, and acrylics.

Suitable thermoplastic polymers include polymers of the thermoplasticresins described above, as well as polymers such as cellulose acetate,polyacrylates, polycaprolactone and polylactic acid.

With respect to the epoxies, all customary di-and polyepoxide monomers,prepolymers or blends thereof are suitable epoxy resins for the practiceof this invention. In one embodiment, suitable epoxy resins are thosethat are liquid at ambient temperature. The di- and polyepoxides may bealiphatic, cycloaliphatic or aromatic compounds. Typical examples ofsuch compounds are the diglycidyl ethers of bisphenol A glycerol orresorcinol, the glycidyl ethers and β-methylglycidyl ethers of aliphaticor cycloaliphatic diols or polyols, including those of hydrogenatedbisphenol A, ethylene glycol, 1,2-propanediol, 1,3-propanediol,1,4-butanediol, diethylene glycol, polyethylene glycol, polypropyleneglycol, glycerol, trimethylolpropane or 1,4-dimethylolcyclohexane or of2,2-bis(4-hydroxycyclohexyl)propane, the glycidyl ethers of di- andpolyphenols, typically resorcinol, 4,4′-dihydroxydiphenylmethane,4,4′-dihydroxydiphenyl-2,2-propane, novolaks and1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, Further examples are N-glycidylcompounds, including diglycidyl compounds of ethylene urea,1,3-propylene urea or 5-dimethylhydantoin or of4,4′-methylene-5,5′-tetramethyldihydantoin, or those such as triglycidylisocyanurate, or biodegradable/bio-derived epoxies (vegetableoil-based).

Further glycidyl compounds of technical importance are the glycidylesters of carboxylic acids, especially di-and polycarboxylic acids.Typical examples are the glycidyl esters of succinic acid, adipic acid,azelaic acid, sebacic acid, phthalic acid, terephthalic acid, tetraandhexahydrophthalic acid, isophthalic acid or trimellitic acid or ofpartially polymerized, e.g. dimerised, fatty acids.

Exemplary of polyepoxides that differ from glycidyl compounds are thediepoxides of vinylcyclohexene and dicyclopentadiene,3-(3′,4′-epoxycyclohexyl)-8,9-epoxy-2,4-dioxaspiro[5.5]undecane, the3′,4′-epoxycyclohexylmethyl ester of 3,4-epoxycyclohexanecarboxylicacid, butadiene diepoxide or isoprene diepoxide, epoxidized linoleicderivatives or epoxidized polybutadiene.

Other suitable epoxy resins are diglycidyl ethers or advanced diglycidylethers of dihydric phenols or dihydric aliphatic alcohols of 2 to 4carbon atoms, preferably the diglycidyl ethers or advanced diglycidylethers of 2,2-bis(4-hydroxyphenyl)propane andbis(4-hydroxyphenyl)methane or a mixture of these epoxy resins.

Suitable epoxy resin hardeners for the practice of this invention may beany suitable epoxy resin hardener, typically selected from primary andsecondary amines and their adducts, cyanamide, dicyandiamide,polycarboxylic acids, anhydrides of polycarboxylic acids, polyamines,polyamino-amides, polyadducts of amines and polyepoxides and polyols.

A variety of amine compounds (mono, di or polyamines) can be used as ahardener such as aliphatic amines (diethylene triamine, polyoxypropylenetriamine etc), cycloaliphatic amines (isophorone diamine, aminoethylpiperazine or diaminocyclohexane etc), or aromatic amines (diaminodiphenyl methane, xylene diamine, phenylene diamine etc). Primary andsecondary amines broadly can serve as hardening agents while tertiaryamines generally act as catalysts.

Although epoxy hardeners are typically amines, other options exist andthese will give extra flexibility to accommodate chemical agents thatmight be unstable or soluble in the presence of amine, or allow abroader range of cure rates to be achieved.

For example, other suitable hardeners are anhydrides of polycarboxylicacids, typically phthalic anhydride, nadic anhydride, methylnadicanhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalicanhydride and, in addition, tetrahydrophthalic anhydride andhexahydrophthalic anhydride.

In accordance with the invention, Pickering colloidal emulsionstabilizers of any type may be used to stabilize emulsions prior to thestep of solidifying the dispersed phase into a solid polymer matrix,regardless of polymer matrix type, where the dispersed phase contains achemical agent such as an agrochemical active ingredient, and optionallywhere the dispersed phase contains a means to control the matrixpermeability and thereby the agrochemical active ingredient release rateupon application.

More specifically, solids, such as silicas and clays, have been taughtin the literature for use as viscosity modifiers in agrochemicalformulations to inhibit gravity-driven sedimentation or cream separationby forming a network or gel throughout the continuous phase, therebyincreasing the low-shear viscosity, and slowing the movement of smallparticles, surfactant micelles or emulsion droplets. The colloidalsolids of the present invention instead serve as a processing aid tostabilize the droplets containing the resin monomers during cure byadsorbing to the transient liquid-liquid interface, thereby forming abarrier around the curing droplets so that contacting or neighbouringcuring droplets are not able to coalesce, irrespective of whether or notthe curing droplets have collected in a sediment or a cream layer. It ispossible to distinguish the two different functions—rheologicalmodification or emulsion stabilization, by a functional test such asdescribed below. The effectiveness of the colloidal solid in stabilizingthe emulsions of curing polymer droplets depends on particle size,particle shape, particle concentration, particle wettability and theinteractions between particles. The colloidal solids must be smallenough so that they can coat the surfaces of the dispersed curing liquidpolymer droplets, and the curing liquid droplets must be sufficientlysmall for acceptable dispersion stability against sedimentation of theresulting solid polymer particles if the dispersion concentratecontaining such particles is diluted for use. The final polymerparticles (and hence, the colloidal solids) will also need to be smallenough to provide an acceptably even product distribution at the targetsite. The colloidal solid also must have sufficient affinity for boththe liquids forming the dispersed and continuous phases so that they areable to adsorb to the transient liquid-liquid interface and therebystabilize the emulsion during cure. This wetting characteristic,particle shape and suitability for Pickering-type emulsion stabilizationmay be readily assessed by preparing a control formulation lacking thecolloidal solid as emulsion stabilizer. In such a case the curing liquidpolymer droplets coalesce and form a consolidated mass instead of adispersion of fine solid polymer particles.

In one embodiment, the colloidal solids have a number-weighted medianparticle size diameter as measured by scanning electron microscopy of0.01-2.0 microns, particularly 0.5 microns or less, more particularly0.1 microns or less.

A wide variety of solid materials may be used as colloidal stabilizersfor preparing the dispersions of the present invention including carbonblack, metal oxides, metal hydroxides, metal carbonates, metal sulfates,polymers, silica and clays. Suitable colloidal stabilizers are insolublein any of the liquid phases present in preparation of the concentrateformulation. If an agrochemical active ingredient has suitably lowsolubility in any liquid used to dilute the final composition, and inboth the continuous and (transient) dispersed liquid phases, that isbelow about 100 ppm at room temperature, and can be prepared at asuitable particle size, and has suitable wetting properties for thetransient liquid-liquid interface as described above, then it is alsopossible that this active ingredient can serve as the colloidalstabilizer. Examples of particulate inorganic materials are oxycompounds of at least one of calcium, magnesium, aluminium and silicon(or derivatives of such materials), such as silica, silicate, marble,clays and talc. Particulate inorganic materials may be either naturallyoccurring or synthesized in reactors. The particulate inorganic materialmay be a mineral chosen from, but not limited to, kaolin, bentonite,alumina, limestone, bauxite, gypsum, magnesium carbonate, calciumcarbonate (either ground or precipitated), perlite, dolomite, diatomite,huntite, magnesite, boehmite, sepiolite, palygorskite, mica,vermiculite, illite, hydrotalcite, hectorite, halloysite and gibbsite.Further suitable clays (for example aluminosilicates) include thosecomprising the kaolinite, montmorillonite or illite groups of claymineral. Other specific examples are attapulgite, laponite andsepiolite. Polymers that flocculate the colloids (such as xanthan in thecase of colloidal kaolin) can also improve the stability of Pickeringemulsions.

In one embodiment, non-porous particulate inorganic materials aredistributed within the polymer particles along with the agrochemicallyactive ingredient to serve as an optional diffusion barrier. Thediffusion barrier is prepared by dissolving or suspending such materialsalong with the (e.g., water-sensitive) agriculturally active ingredientin the non-aqueous curable liquid mixture that is used to prepare thethermoset or thermoplastic resin polymer particles which serve asdispersed phase b). Suitable non-porous particulate diffusion barriermaterials include carbon black, metal oxides, metal hydroxides, metalcarbonates, metal sulfates, polymers, silica, mica and clays.

In one aspect of the invention, the particulate inorganic material iskaolin clay. Kaolin clay is also referred to as china clay or hydrouskaolin, and contains predominantly mineral kaolinite (Al₂Si₂O₅(OH)₄), ahydrous aluminium silicate (or aluminosilicate).

In one aspect of the invention, the particulate inorganic material maybe surface modified. Surface-modified means that the inorganic particlesurface has been modified so as to have reactive groups. The surface ofthe particles may be modified using a wide variety of chemicals, withthe general structure X-Y-Z, in which X is a chemical moiety with a highaffinity for the particle surface; Z is a (reactive) chemical moietywith a desired functionality; and Y is a chemical moiety that links Xand Z together.

X may be, for example, an alkoxy-silane group such as tri-ethoxysilaneor tri-methoxysilane or trichlorosilane, which is particularly usefulwhen the particles have silanol (SiOH) groups on their surface. X mayalso be, for example, an acid group (such as a carboxylic or an acrylicacid group) which is particularly useful when the particles have basicgroups on their surface. X may also be, for example, a basic group (suchas an amine group), an epoxy group, or an unsaturated group (such as anacrylic or vinyl group).

Y can be any chemical group that links X and Z together, for example apolyamide, a polyisocyanate, a polyester or an alkylene chain; moresuitably it is an alkylene chain; and even more suitably it is a C₂₋₆alkylene chain, such as ethylene or propylene.

Reactive groups Z can be selected from any groups, and may be differentfrom Y, which can be used to react with a cross-linker.

The type and amount of colloidal solid is selected so as to provideacceptable physical stability of the composition during cure,polymerization, solvent evaporation or other polymer solidificationprocesses. This can readily be determined by one of skill in the art byroutine evaluation of a range of compositions having different amountsof this component. For example, the ability of the colloidal solids tostabilize the composition can be verified by preparing a test samplewith the colloidal solid and it can be confirmed that the emulsion ofdroplets is stable and does not exhibit coalescence. Coalescence isapparent by the formation of large droplets visible to the eye, andultimately by the formation of a layer of liquid monomers, polymer meltor polymer solution within the formulation. Physical stability of thecomposition during cure, polymerization, solvent evaporation or otherpolymer solidification is acceptable if no significant coalescence isevident and the solid polymer particles are present as a finedispersion.

For example, in one embodiment the colloidal solids are employed in anamount of from 1 to 80%, particularly from 4 to 50% by weight of thedispersed phase. Mixtures of colloidal solids may be employed.

In one embodiment, one or more surfactants may optionally be used inaddition to Pickering emulsion colloidal stabilizers, in order toconveniently control the size of the emulsion droplets in conjunctionwith the shear rate applied during the emulsification process. Ifpresent, the one or more surfactants are employed in an amount of from0.1% to 90%, particularly from 1% to 60% by weight of the Pickeringemulsion colloidal stabilizers. In a particular embodiment, thesurfactants are chosen to have a low HLB such as 6 or below. In anotherparticular embodiment, the surfactant is alkylamine 2-mole ethoxylate,whether the alkyl group contains from about 8 to about 18 carbon atoms.

The following examples illustrate further some of the aspects of theinvention but are not intended to limit its scope. Where not otherwisespecified throughout this specification and claims, percentages are byweight.

EXAMPLES 1-4 Illustrating the Use of Different Continuous Phase Liquids

A resin mixture A of 19.1 g 635 Thin Epoxy Resin (US Composites of WestPalm Beach, Fla.) and 9.5 g 556 2:1 Epoxy Hardener (also of USComposites) was prepared. The following liquid continuous phase samplesof 10 g liquid were then prepared each by vortex mixing with 0.2 gAerosil 200 fumed silica as colloidal stabilizer: 9:1 ethyleneglycol:water, 9:1 PEG200:water, 9:1 glycerine:water, and water. A 0.2 gof resin mixture A was then introduced into each continuous phase sampleand dispersed by vortex mixing. The samples were placed on a platformshaker overnight at room temperature and then examined by lightmicroscopy. In every case the presence of a dispersion of epoxy resinparticles of diameter approximately 100 microns was confirmed. Theseexamples show that small particles of solid epoxy resin may be formed ina variety of different liquid continuous aqueous phases.

EXAMPLES 5-7 Illustrating the Use of Different Colloids to Stabilize theResin Before Curing

A resin mixture B was prepared by mixing together 9 g 635 Thin EpoxyResin, 1.5 g of finely milled difenoconazole and 4.5 g 556 2:1 EpoxyHardener. The following liquid continuous phases were then prepared eachby vortex mixing: 0.2 g Aerosil 200 fumed silica in 9.8 g water, and 0.2g fumed aluminum oxide in 9.8 g water. 0.2 g of resin mixture B was thenintroduced into each continuous phase sample and dispersed by vortexmixing. The samples were placed on a platform shaker overnight at roomtemperature and then examined by light microscopy. In every case thepresence of a dispersion of fine epoxy resin particles of diameterapproximately 100 microns was confirmed. In addition, a sample wasprepared where the liquid continuous phase did not contain any colloidalsolids, and the result was a large deposit of solid epoxy materialadhered to the container wall. This example shows that a variety ofdifferent colloidal solids may be used to stabilize dispersions of epoxyresin but that if no colloidal solid is used the resin simply coalescesand ultimately solidifies into a solid mass.

EXAMPLES 8-16 Incorporating Different AI's into the Polymer Matrix

Nine different individual resin mixtures were prepared by mixingtogether 8 g 635 Thin Epoxy Resin, 4 g 556 2:1 Epoxy Hardener andbetween 1.0 and 1.5 g of the following finely milled active ingredients:atrazine, azoxystrobin, bicylopyrone, cyproconazole, difenoconazole,mesotrione, prodiamine, thiabendazole, thiamethoxam. By inspection itwas clear that at these concentrations bicylopyrone and mesotrione werefully dissolved in the liquid resin, most of the cyproconazole wasdissolved, and the other AI's had not appreciably dissolved. 1 g of eachof these resin mixtures was separately dispersed by vortex mixing into10 g continuous phase liquid samples each containing 0.2 g Aerosil 200fumed silica dispersed in 9.8 g water. The samples were placed on aplatform shaker overnight at room temperature and then examined by lightmicroscopy. In every case the presence of a dispersion of epoxy resinparticles of diameter approximately 100 microns was confirmed. Crystalsof the active ingredient were visible inside the epoxy particles underpolarized light, except that in the cases of bicyclopyrone andmesotrione individual crystals were not visible as these activeingredients had dissolved in the epoxy resin—in these cases the entireepoxy resin particle was slightly birefringent indicating the presenceof crystal domains within the matrix. These examples show that a widevariety of different active ingredients may be efficiently captured inthe epoxy resin particles, regardless of whether they are insoluble,partly-soluble or fully-soluble in the resin, and with no significantmodification needed in the process nor the presence of other components.

EXAMPLES 17-18 Illustrating the Entrapment of an Active Ingredient inPolystyrene and Polyacrylate Matrices A. Formulation Preparation

The dispersed phase is premixed with a shear mixer as described in table1 below. The continuous phase is premixed with low shear mixer. Thepremixed dispersed phase is added into the continuous phase, and thenblend with high shear mixer for 5-10 min. In order to polymerize, theemulsified formulation is treated with high temperature (70° C.) for 8hr. Average diameter of particles was determined by Malvern® mastersizer.

TABLE 1 Example 17 Example 18 Dispersed Atrazine 6% Atrazine 6% phaseStyrene monomer Methylmethacrylate monomer 14.7% 14.7% Methyl ethylketone peroxide 0.3% Methyl ethyl ketone peroxide 0.3% ContinuousAerosil A300 3% Aerosil A300 3% phase Phosphoric acid Phosphoric acid(8%) 0.05% (8%) 0.05% water 75.95% water 75.95% Mean 13 14 particlediameter (μm)

EXAMPLES 19-20 Illustrating Control of Release Rate by Incorporation ofa Mobile Non-cross-linkable Molecule into the Polymer Matrix andExamples 21-22 Illustrating the Entrapment of Liquid Active IngredientsA. Formulation Preparation

The dispersed phase is premixed with a low shear mixer as described intable 2 below. The continuous phase is premixed with a low shear mixer.The premixed dispersed phase is added into the continuous phase, andthen mix with a high shear mixer for 5-10 min. For accelerating theepoxy curing reaction, the mixed formulation was treated with hightemperature (70° C.) for 3 hr. Average diameter of particles wasdetermined by Malvern® master sizer.

B. Release Rate

The cured compositions 19 and 20 were diluted in water with appropriateemulsifiers (Toximul TA-6, Stepfac 8180 and Toximul 8320 etc) in a glassbottle and then stirred. The concentration of active ingredient wasmonitored by HPLC analysis.

TABLE 2 Example 19 Example 20 Example 21 Example 22 DispersedThiamethoxam Thiamethoxam Mefenoxam 5% s-metolachlor 5% phase 5% 5%Epoxy 635 10% Epoxy 635 10% Epoxy 635 10% Epoxy 635 9% Hardener 556 5%Hardener 556 5% Hardener 556 5% Hardener 556 4.5% Polyethyleneglycol (Mw= 200) 1.5% Continuous Aerosil A200 2% Aerosil A200 2% Aerosil A200 2%Aerosil A200 2% phase water 78% water 78% water 78% water 78% Average 5545 25 27 particle diameter (μm) % ai release  0 hr 0.9 1.8 42 24 hrs 1.22.3 51 48 hrs 1.4 2.5 56

EXAMPLES 21-24 Illustrating Pickering Emulsions Using Clay andFlocculating Polymers A. Formulation Preparation

The dispersed phase is premixed with a shear mixer as described in table3 below. The continuous phase is premixed with low shear mixer. Thepremixed dispersed phase is added into the continuous phase, and thenblend with a high shear mixer for 5-10 min. In order to polymerize, theemulsified formulation is treated with high temperature (70° C.) for 8hr. Average diameter of particles was determined by Malvern® mastersizer.

TABLE 3 21 22 23 24 Dispersed Mefenoxam 7.5 phase s-metolachlor 7.5Tefluthrin 7.5 Propiconazole 7.5 Resorcinol 5 5 5 5 diglycidyl etherPolyoxypropylene 2.5 2.5 2.5 2.5 diamine (Mn = 230 Da) Continuous Clay(kaolin) 1.2 1.2 1.2 1.2 phase Xanthan Pregel 2 2 2 2 (2%) Phosphoricacid 0.1 (8.5%) water 18.8 18.8 18.8 18.7 Average Particle 30 25 17 30size (um)

Although only a few exemplary embodiments of this invention have beendescribed in detail above, those skilled in the art will readilyappreciate that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of this invention. Accordingly, all such modifications areintended to be included within the scope of this invention as defined inthe following claims.

1. An aqueous liquid dispersion concentrate composition comprising (a) acontinuous aqueous liquid phase; and (b) at least one dispersed, solidphase comprising polymer particles having a mean particle size of atleast one micron and prepared from either a curable or polymerizableresin or a solidifiable thermoplastic polymer, wherein the outsidesurfaces of the polymer particles comprise a colloidal solid materialand wherein the polymer particles have at least one chemical agentdistributed therein.
 2. The composition of claim 1, wherein the chemicalagent is an agrochemically active ingredient.
 3. The composition ofclaim 1, wherein the colloidal solid material is present in an amounteffective to stabilize the polymer particles in an emulsion state duringthe process which is used to prepare the dispersed phase.
 4. Thecomposition of claim 2, wherein the agriculturally active ingredientcomprises a solid and is distributed within a dispersed solid phase oris a liquid and is distributed within a dispersed solid phase.
 5. Thecomposition of claim 1, wherein the dispersed phase comprises at leastone non-cross-linkable mobile chemical such that the extraction of thischemical from the dispersed phase renders it porous in a manner thatallows the active ingredient to diffuse out.
 6. The composition of claim1, wherein the polymer molecules that comprise the polymer particlescontain hydrophilic groups that hydrate on exposure to water in a mannerthat renders the polymer particles more permeable such that they allowthe active ingredient to diffuse out.
 7. The composition of claim 1,wherein each dispersed phase optionally comprises at least onenon-porous particulate mineral that acts as a diffusion barrier to slowthe release of the active ingredient.
 8. The composition of claim 1,wherein the polymer particles are thermoset.
 9. The composition of claim1, wherein the polymer particles are thermoplastic.
 10. The compositionof claim 1, wherein the continuous phase (a) comprises water and asubstantially water-miscible, non-aqueous liquid.
 11. The composition ofclaim 10, wherein the substantially water-miscible, non-aqueous liquidis selected from propylene carbonate, ethylene glycol, diethyleneglycol, triethylene glycol, propylene glycol, dipropylene glycol,tripropylene glycol, butylene glycol, hexylene glycol, polyethyleneglycols having a molecular weight of up to about 800, di(propyleneglycol) methyl ether acetate, propylene glycol diacetate, triethylphosphate; ethyl lactate, gamma-butyrolactone, propanol,tetrahydrofurfuryl alcohol, N-methyl pyrrolidone, dimethyl lactamide,and mixtures thereof.
 12. The composition of claim 1, wherein thecontinuous phase (a) comprises water and a water-soluble solute.
 13. Thecomposition of claim 12, wherein the water-soluble solute is selectedfrom an acid, a base, a salt, a sugar, a polysaccharide, a protein, anamino acid, betaine and mixtures thereof.
 14. The composition of claim2, wherein the continuous phase (a) further comprises at least oneagrochemically active ingredient and that active ingredient is in thestate selected from a solution, an emulsion, a microemulsion, or asuspension of microcapsules or fine particles.
 15. The composition ofclaim 1, wherein the continuous phase (a) further comprises one or moresurfactants or dispersants.
 16. The composition of claim 1, wherein thecolloidal solid comprises a particulate inorganic material distributedat the surface of the polymer particles.
 17. The composition of claim 2,wherein the colloidal solid comprises an agrochemically activeingredient in fine particulate form and functional as a Pickeringstabilizer that is distributed at the surface of the polymer particles.18. The composition of claim 1, wherein each dispersed phase (b)optionally further comprises at least one non-cross-linkable mobilechemical selected from a surfactant, a polymer, a copolymer, an acid, abase, a natural or synthetic oil or alcohol, a substantiallywater-soluble compound and a substantially water-insoluble compound. 19.The composition of claim 1, wherein each dispersed solid phase (b)comprises a cured epoxy resin polymer.
 20. The composition of claim 1,wherein each dispersed solid phase (b) comprises a cured phenolic resinpolymer.
 21. The composition of claim 1, wherein each dispersed solidphase (b) comprises a cured polyurethane polymer.
 22. The composition ofclaim 1, wherein each dispersed solid phase (b) comprises a curedpolyurea resin polymer.
 23. The composition of claim 1, wherein eachdispersed solid phase (b) comprises a cured aminoplast resin polymer.24. The composition of claim 1, wherein each dispersed solid phase (b)comprises a polyester or vinyl ester resin polymer.
 25. The compositionof claim 1, wherein each dispersed solid phase (b) comprises athermoplastic polystyrene or polyacrylate polymer or biodegradablethermoplastic polymer.
 26. The composition of claim 19, wherein (b)comprises a cured epoxy resin polymer matrix prepared by curing an epoxyresin selected from di-and polyepoxide monomers, prepolymers,biodegradable epoxy resins or blends thereof with a hardener selectedfrom primary and secondary amines and their adducts, cyanamide,dicyandiamide, polycarboxylic acids, anhydrides of polycarboxylic acids,polyamines, polyamino-amides, polyadducts of amines and polyepoxides,polyols and mixtures thereof
 27. The composition of claim 1, whereineach dispersed solid phase comprises polymer particles with meandiameter between 1 and 200 microns.
 28. The composition of claim 1,wherein the colloidal solid comprises no more than about 80 wt % of thedispersed solid phase.
 29. A method of preventing or combatinginfestation of plant species by pests, or regulating plant growth bydiluting an effective amount of concentrate composition according toclaim 2 with an aqueous liquid carrier selected from water and liquidfertilizer, and applying the dilute composition to the plant species orlocus thereof.
 30. A process for making an aqueous liquid dispersionconcentrate incorporating at least one agrochemically active ingredientcomprising the steps of: a. dissolving or suspending at least oneagrochemically active ingredient in a liquid curable, solidifiable orpolymerizable resin optionally containing at least onenon-cross-linkable mobile chemical, optionally containing a non-porousparticulate mineral, and optionally containing a chemical curing agent;b. combining said solution or suspension with an aqueous liquidcontaining a colloidal solid emulsion stabilizer and optionally achemical curing agent and applying mechanical agitation sufficient toform an emulsion of said solution or suspension; and c. effecting cure,solidification or polymerization of the resin to produce an aqueousliquid dispersion of polymer particles which contain at least oneagrochemically active ingredient and a colloidal solid distributed atthe surface of the polymer particles.
 31. The process according to claim30, wherein the polymerizable resin is selected from epoxy,polyisocyanate, polyamine, aminoplast, phenolic and polyester.
 32. Theprocess according to claim 31, wherein the polymerizable resin is athermosetting epoxy resin.
 33. The process according to claim 32,wherein the epoxy resin comprises a diglycidyl ether of bisphenol A,glycerol, polypropyleneoxide or resorcinol, or a mixture of two or moreof these ethers.
 34. The process according to claim 32, wherein curingof the epoxy resin is accomplished using an amine hardener.
 35. Theprocess according to claim 34, wherein curing is accomplished by usingan amine hardener comprising a poly(oxypropylene)diamine.
 36. Theprocess according to claim 30, where the colloidal solid emulsionstabilizer is selected from carbon black, metal oxides, metalhydroxides, metal carbonates, metal sulfates, polymers, silica andclays.
 37. The process according to claim 36, where the colloidal solidemulsion stabilizer is an agrochemically active ingredient in finelydivided form.
 38. A process for making an aqueous liquid dispersionconcentrate incorporating at least one agrochemically active ingredientcomprising the steps of: a. dissolving or suspending at least oneagrochemically active ingredient in a solution of a thermoplasticpolymer in a volatile solvent optionally containing a non-porousparticulate mineral and optionally containing a non-cross-linkablemobile chemical; b. combining said solution or suspension with anaqueous liquid containing a colloidal solid emulsion stabilizer andapplying mechanical agitation sufficient to form an emulsion of saidsolution or suspension; and c. applying heat to evaporate the volatilesolvent to produce an aqueous liquid dispersion of polymer particleswhich contain at least one agrochemically active ingredient and acolloidal solid distributed at the surface of the polymer particles. 39.A process for making an aqueous liquid dispersion concentrateincorporating at least one agrochemically active ingredient comprisingthe steps of: a. dissolving or suspending at least one agrochemicallyactive ingredient in a melt of a thermoplastic polymer optionallycontaining a non-porous particulate mineral and optionally containing anon-cross-linkable mobile chemical; b. combining said solution orsuspension with an aqueous liquid containing a colloidal solid emulsionstabilizer and applying mechanical agitation sufficient to form anemulsion of said solution or suspension; and c. cooling the emulsion tosolidify the disperse phase and thereby produce an aqueous liquiddispersion of polymer particles that contain at least one agrochemicallyactive ingredient and a colloidal solid distributed at the surface ofthe polymer particles.
 40. The process according to claim 38, where thecolloidal solid emulsion stabilizer is selected from carbon black, metaloxides, metal hydroxides, metal carbonates, metal sulfates, polymers,silica and clays.
 41. The process according to claim 38, where thecolloidal solid emulsion stabilizer is an agrochemically activeingredient in finely divided form.
 42. The process according to claim30, where the colloidal solid emulsion stabilizer may be surfacemodified isotropically or otherwise, in a way that allows it to reactchemically with a cross-linking agent that may comprise thepolymerizable resin or another agent added through the continuous phase.43. The process according to claim 30, wherein the continuous phase iswater and the colloidal solid is a hydrophilic fumed silica.
 44. Theprocess according to claim 30, wherein the continuous phase compriseswater and a substantially water-miscible, non-aqueous liquid, and thecolloidal solid is a hydrophilic fumed silica.
 45. The process accordingto claim 30, wherein the continuous phase is a solution of xanthanpolysaccharide in water and the colloidal solid is kaolin clay.
 46. Apolymer particle comprising at least one entrapped agrochemically activeingredient that is either homogeneously on non-homogeneously distributedwithin such particle or is present in the form of domains within suchparticle, and wherein the outside surface region of such particlecomprises a colloidal solid material, and optionally comprising at leastone mobile non-cross-linkable chemical.